document_title: Mineral

question_text: what are the 5 main characteristics of a mineral

question_tokens: what are the 5 main characteristics of a mineral

root

text: Mineral

text: Definition

text: Basic definition

text: One definition of a mineral encompasses the following criteria:[3]

tag: p

text:
Formed by a natural process (anthropogenic compounds are excluded).
Stable or metastable at room temperature (25 °C). In the simplest sense, this means the mineral must be solid. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, and water ice, which is solid only below 0 °C; because these two minerals were described before 1959, they were grandfathered by the International Mineralogical Association (IMA).[4][5] Modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy.
Represented by a chemical formula. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution; pure substances are not usually found because of contamination or chemical substitution. For example, the olivine group is described by the variable formula (Mg, Fe)2SiO4, which is a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula. Mineral species themselves could have a variable compositions, such as the sulfide mackinawite, (Fe, Ni)9S8, which is mostly a ferrous sulfide, but has a very significant nickel impurity that is reflected in its formula.[3][6]
Ordered atomic arrangement. This generally means crystalline, however, crystals are also periodic, so the broader criterion is used instead.[3] An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage.[7] There have been several recent proposals to classify biogenic or amorphous substances as minerals. The formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes."[8]
Usually abiogenic (not resulting from the activity of living organisms). Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced entirely by biological processes without a geological component (e.g., urinary calculi, oxalate crystals in plant tissues, shells of marine molluscs, etc.) and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound, then the product can be accepted as a mineral."[8]

text: The first three general characteristics are less debated than the last two.[3]

text: Recent advances

text: Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes.[9][10] The organic class includes a very rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names.[11][12] According to these new rules, "mineral species can be grouped in a number of different ways, on the basis of chemistry, crystal structure, occurrence, association, genetic history, or resource, for example, depending on the purpose to be served by the classification."[11]

text: The Nickel (1995)[clarification needed] exclusion of biogenic substances was not universally adhered to. For example, Lowenstam (1981) stated that "organisms are capable of forming a diverse array of minerals, some of which cannot be formed inorganically in the biosphere."[13] The distinction is a matter of classification and less to do with the constituents of the minerals themselves. Skinner (2005) views all solids as potential minerals and includes biominerals in the mineral kingdom, which are those that are created by the metabolic activities of organisms. Skinner expanded the previous definition of a mineral to classify "element or compound, amorphous or crystalline, formed through biogeochemical processes," as a mineral.[14]

text: Recent advances in high-resolution genetics and X-ray absorption spectroscopy are providing revelations on the biogeochemical relations between microorganisms and minerals that may make Nickel's (1995) biogenic mineral exclusion obsolete and Skinner's (2005) biogenic mineral inclusion a necessity.[8][14] For example, the IMA commissioned "Environmental Mineralogy and Geochemistry Working Group"[15] deals with minerals in the hydrosphere, atmosphere, and biosphere. The group's scope includes mineral-forming microorganisms, which exist on nearly every rock, soil, and particle surface spanning the globe to depths of at least 1600 metres below the sea floor and 70 kilometres into the stratosphere (possibly entering the mesosphere).[16][17][18] Biogeochemical cycles have contributed to the formation of minerals for billions of years. Microorganisms can precipitate metals from solution, contributing to the formation of ore deposits. They can also catalyze the dissolution of minerals.[19][20][21]

text: Prior to the International Mineralogical Association's listing, over 60 biominerals had been discovered, named, and published.[22] These minerals (a sub-set tabulated in Lowenstam (1981)[13]) are considered minerals proper according to the Skinner (2005) definition.[14] These biominerals are not listed in the International Mineral Association official list of mineral names,[23] however, many of these biomineral representatives are distributed amongst the 78 mineral classes listed in the Dana classification scheme.[14] Another rare class of minerals (primarily biological in origin) include the mineral liquid crystals that have properties of both liquids and crystals. To date over 80,000 liquid crystalline compounds have been identified.[24][25]

text: The Skinner (2005) definition of a mineral takes this matter into account by stating that a mineral can be crystalline or amorphous, the latter group including liquid crystals.[14] Although biominerals and liquid mineral crystals, are not the most common form of minerals,[26] they help to define the limits of what constitutes a mineral proper. The formal Nickel (1995) definition explicitly mentioned crystallinity as a key to defining a substance as a mineral. A 2011 article defined icosahedrite, an aluminium-iron-copper alloy as mineral; named for its unique natural icosahedral symmetry, it is a quasicrystal. Unlike a true crystal, quasicrystals are ordered but not periodic.[27][28]

text: Rocks, ores, and gems

text: Minerals are not equivalent to rocks. A rock is either an aggregate of one or more minerals[29] or mineraloids. Some rocks, such as limestone or quartzite, are composed primarily of one mineral—calcite or aragonite in the case of limestone, and quartz in the latter case.[30][31] Other rocks can be defined by relative abundances of key (essential) minerals; a granite is defined by proportions of quartz, alkali feldspar, and plagioclase feldspar.[32] The other minerals in the rock are termed accessory, and do not greatly affect the bulk composition of the rock. Rocks can also be composed entirely of non-mineral material; coal is a sedimentary rock composed primarily of organically derived carbon.[29][33]

text: In rocks, some mineral species and groups are much more abundant than others; these are termed the rock-forming minerals. The major examples of these are quartz, the feldspars, the micas, the amphiboles, the pyroxenes, the olivines, and calcite; except the last one, all of the minerals are silicates.[34] Overall, around 150 minerals are considered particularly important, whether in terms of their abundance or aesthetic value in terms of collecting.[35]

text: Commercially valuable minerals and rocks are referred to as industrial minerals. For example, muscovite, a white mica, can be used for windows (sometimes referred to as isinglass), as a filler, or as an insulator.[36] Ores are minerals that have a high concentration of a certain element, typically a metal. Examples are cinnabar (HgS), an ore of mercury, sphalerite (ZnS), an ore of zinc, or cassiterite (SnO2), an ore of tin. Gems are minerals with an ornamental value, and are distinguished from non-gems by their beauty, durability, and usually, rarity. There are about 20 mineral species that qualify as gem minerals, which constitute about 35 of the most common gemstones. Gem minerals are often present in several varieties, and so one mineral can account for several different gemstones; for example, ruby and sapphire are both corundum, Al2O3.[37]

text: Nomenclature and classification

text: Minerals are classified by variety, species, series and group, in order of increasing generality. The basic level of definition is that of mineral species, each of which is distinguished from the others by unique chemical and physical properties. For example, quartz is defined by its formula, SiO2, and a specific crystalline structure that distinguishes it from other minerals with the same chemical formula (termed polymorphs). When there exists a range of composition between two minerals species, a mineral series is defined. For example, the biotite series is represented by variable amounts of the endmembers phlogopite, siderophyllite, annite, and eastonite. In contrast, a mineral group is a grouping of mineral species with some common chemical properties that share a crystal structure. The pyroxene group has a common formula of XY(Si,Al)2O6, where X and Y are both cations, with X typically bigger than Y; the pyroxenes are single-chain silicates that crystallize in either the orthorhombic or monoclinic crystal systems. Finally, a mineral variety is a specific type of mineral species that differs by some physical characteristic, such as colour or crystal habit. An example is amethyst, which is a purple variety of quartz.[38]

text: Two common classifications, Dana and Strunz, are used for minerals; both rely on composition, specifically with regards to important chemical groups, and structure. James Dwight Dana, a leading geologist of his time, first published his System of Mineralogy in 1837; as of 1997, it is in its eighth edition. The Dana classification assigns a four-part number to a mineral species. Its class number is based on important compositional groups; the type gives the ratio of cations to anions in the mineral; and the last two numbers group minerals by structural similarity within a given type or class. The less commonly used Strunz classification, named for German mineralogist Karl Hugo Strunz, is based on the Dana system, but combines both chemical and structural criteria, the latter with regards to distribution of chemical bonds.[39]

text: As of March 2017[update], 5,237 mineral species are approved by the IMA.[2] They are most commonly named after a person (45%), followed by discovery location (23%); names based on chemical composition (14%) and physical properties (8%) are the two other major groups of mineral name etymologies.[38][40] The common suffix -ite of mineral names descends from the ancient Greek suffix – ί τ η ς (-ites), meaning "connected with or belonging to".[41]

text: Chemistry

text: The abundance and diversity of minerals is controlled directly by their chemistry, in turn dependent on elemental abundances in the Earth. The majority of minerals observed are derived from the Earth's crust. Eight elements account for most of the key components of minerals, due to their abundance in the crust. These eight elements, summing to over 98% of the crust by weight, are, in order of decreasing abundance: oxygen, silicon, aluminium, iron, magnesium, calcium, sodium and potassium. Oxygen and silicon are by far the two most important – oxygen composes 47% of the crust by weight, and silicon accounts for 28%.[42]

text: The minerals that form are directly controlled by the bulk chemistry of the parent body. For example, a magma rich in iron and magnesium will form mafic minerals, such as olivine and the pyroxenes; in contrast, a more silica-rich magma will crystallize to form minerals that incorporate more SiO2, such as the feldspars and quartz. In a limestone, calcite or aragonite (both CaCO3) form because the rock is rich in calcium and carbonate. A corollary is that a mineral will not be found in a rock whose bulk chemistry does not resemble the bulk chemistry of a given mineral with the exception of trace minerals. For example, kyanite, Al2SiO5 forms from the metamorphism of aluminium-rich shales; it would not likely occur in aluminium-poor rock, such as quartzite.

text: The chemical composition may vary between end member species of a solid solution series. For example, the plagioclase feldspars comprise a continuous series from sodium-rich end member albite (NaAlSi3O8) to calcium-rich anorthite (CaAl2Si2O8) with four recognized intermediate varieties between them (given in order from sodium- to calcium-rich): oligoclase, andesine, labradorite, and bytownite.[43] Other examples of series include the olivine series of magnesium-rich forsterite and iron-rich fayalite, and the wolframite series of manganese-rich hübnerite and iron-rich ferberite.

text: Chemical substitution and coordination polyhedra explain this common feature of minerals. In nature, minerals are not pure substances, and are contaminated by whatever other elements are present in the given chemical system. As a result, it is possible for one element to be substituted for another.[44] Chemical substitution will occur between ions of a similar size and charge; for example, K+ will not substitute for Si4+ because of chemical and structural incompatibilities caused by a big difference in size and charge. A common example of chemical substitution is that of Si4+ by Al3+, which are close in charge, size, and abundance in the crust. In the example of plagioclase, there are three cases of substitution. Feldspars are all framework silicates, which have a silicon-oxygen ratio of 2:1, and the space for other elements is given by the substitution of Si4+ by Al3+ to give a base unit of [AlSi3O8]−; without the substitution, the formula would be charge-balanced as SiO2, giving quartz.[45] The significance of this structural property will be explained further by coordination polyhedra. The second substitution occurs between Na+ and Ca2+; however, the difference in charge has to accounted for by making a second substitution of Si4+ by Al3+.[46]

text: Coordination polyhedra are geometric representation of how a cation is surrounded by an anion. In mineralogy, coordination polyhedra are usually considered in terms of oxygen, due its abundance in the crust. The base unit of silicate minerals is the silica tetrahedron – one Si4+ surrounded by four O2−. An alternate way of describing the coordination of the silicate is by a number: in the case of the silica tetrahedron, the silicon is said to have a coordination number of 4. Various cations have a specific range of possible coordination numbers; for silicon, it is almost always 4, except for very high-pressure minerals where compound is compressed such that silicon is in six-fold (octahedral) coordination by oxygen. Bigger cations have a bigger coordination number because of the increase in relative size as compared to oxygen (the last orbital subshell of heavier atoms is different too). Changes in coordination numbers between leads to physical and mineralogical differences; for example, at high pressure such as in the mantle, many minerals, especially silicates such as olivine and garnet will change to a perovskite structure, where silicon is in octahedral coordination. Another example are the aluminosilicates kyanite, andalusite, and sillimanite (polymorphs, as they share the formula Al2SiO5), which differ by the coordination number of the Al3+; these minerals transition from one another as a response to changes in pressure and temperature.[42] In the case of silicate materials, the substitution of Si4+ by Al3+ allows for a variety of minerals because of the need to balance charges.[47]

text: Changes in temperature and pressure, and composition alter the mineralogy of a rock sample. Changes in composition can be caused by processes such as weathering or metasomatism (hydrothermal alteration). Changes in temperature and pressure occur when the host rock undergoes tectonic or magmatic movement into differing physical regimes. Changes in thermodynamic conditions make it favourable for mineral assemblages to react with each other to produce new minerals; as such, it is possible for two rocks to have an identical or a very similar bulk rock chemistry without having a similar mineralogy. This process of mineralogical alteration is related to the rock cycle. An example of a series of mineral reactions is illustrated as follows.[48]

text: Orthoclase feldspar (KAlSi3O8) is a mineral commonly found in granite, a plutonic igneous rock. When exposed to weathering, it reacts to form kaolinite (Al2Si2O5(OH)4, a sedimentary mineral, and silicic acid):

text: Under low-grade metamorphic conditions, kaolinite reacts with quartz to form pyrophyllite (Al2Si4O10(OH)2):

text: As metamorphic grade increases, the pyrophyllite reacts to form kyanite and quartz:

text: Alternatively, a mineral may change its crystal structure as a consequence of changes in temperature and pressure without reacting. For example, quartz will change into a variety of its SiO2 polymorphs, such as tridymite and cristobalite at high temperatures, and coesite at high pressures.[49]

text: Physical properties

text: Classifying minerals ranges from simple to difficult. A mineral can be identified by several physical properties, some of them being sufficient for full identification without equivocation. In other cases, minerals can only be classified by more complex optical, chemical or X-ray diffraction analysis; these methods, however, can be costly and time-consuming. Physical properties applied for classification include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, cleavage and fracture, and specific gravity. Other less general tests include fluorescence, phosphorescence, magnetism, radioactivity, tenacity (response to mechanical induced changes of shape or form), piezoelectricity and reactivity to dilute acids.[50]

text: Crystal structure and habit

text: Crystal structure results from the orderly geometric spatial arrangement of atoms in the internal structure of a mineral. This crystal structure is based on regular internal atomic or ionic arrangement that is often expressed in the geometric form that the crystal takes. Even when the mineral grains are too small to see or are irregularly shaped, the underlying crystal structure is always periodic and can be determined by X-ray diffraction.[3] Minerals are typically described by their symmetry content. Crystals are restricted to 32 point groups, which differ by their symmetry. These groups are classified in turn into more broad categories, the most encompassing of these being the six crystal families.[51]

text: These families can be described by the relative lengths of the three crystallographic axes, and the angles between them; these relationships correspond to the symmetry operations that define the narrower point groups. They are summarized below; a, b, and c represent the axes, and α, β, γ represent the angle opposite the respective crystallographic axis (e.g. α is the angle opposite the a-axis, viz. the angle between the b and c axes):[51]

text:
Crystal family
Lengths
Angles
Common examples

Isometric
a=b=c
α=β=γ=90°
Garnet, halite, pyrite

Tetragonal
a=b≠c
α=β=γ=90°
Rutile, zircon, andalusite

Orthorhombic
a≠b≠c
α=β=γ=90°
Olivine, aragonite, orthopyroxenes

Hexagonal
a=b≠c
α=β=90°, γ=120°
Quartz, calcite, tourmaline

Monoclinic
a≠b≠c
α=γ=90°, β≠90°
Clinopyroxenes, orthoclase, gypsum

Triclinic
a≠b≠c
α≠β≠γ≠90°
Anorthite, albite, kyanite

text: The hexagonal crystal family is also split into two crystal systems – the trigonal, which has a three-fold axis of symmetry, and the hexagonal, which has a six-fold axis of symmetry.

text: Chemistry and crystal structure together define a mineral. With a restriction to 32 point groups, minerals of different chemistry may have identical crystal structure. For example, halite (NaCl), galena (PbS), and periclase (MgO) all belong to the hexaoctahedral point group (isometric family), as they have a similar stoichiometry between their different constituent elements. In contrast, polymorphs are groupings of minerals that share a chemical formula but have a different structure. For example, pyrite and marcasite, both iron sulfides, have the formula FeS2; however, the former is isometric while the latter is orthorhombic. This polymorphism extends to other sulfides with the generic AX2 formula; these two groups are collectively known as the pyrite and marcasite groups.[52]

text: Polymorphism can extend beyond pure symmetry content. The aluminosilicates are a group of three minerals – kyanite, andalusite, and sillimanite – which share the chemical formula Al2SiO5. Kyanite is triclinic, while andalusite and sillimanite are both orthorhombic and belong to the dipyramidal point group. These difference arise correspond to how aluminium is coordinated within the crystal structure. In all minerals, one aluminium ion is always in six-fold coordination by oxygen; the silicon, as a general rule is in four-fold coordination in all minerals; an exception is a case like stishovite (SiO2, an ultra-high pressure quartz polymorph with rutile structure).[53] In kyanite, the second aluminium is in six-fold coordination; its chemical formula can be expressed as Al[6]Al[6]SiO5, to reflect its crystal structure. Andalusite has the second aluminium in five-fold coordination (Al[6]Al[5]SiO5) and sillimanite has it in four-fold coordination (Al[6]Al[4]SiO5).[54]

text: Differences in crystal structure and chemistry greatly influence other physical properties of the mineral. The carbon allotropes diamond and graphite have vastly different properties; diamond is the hardest natural substance, has an adamantine lustre, and belongs to the isometric crystal family, whereas as graphite is very soft, has a greasy lustre, and crystallises in the hexagonal family. This difference is accounted by differences in bonding. In diamond, the carbons are in sp3 hybrid orbitals, which means they form a framework where each carbon is covalently bonded to four neighbours in a tetrahedral fashion; on the other hand, graphite is composed of sheets of carbons in sp2 hybrid orbitals, where each carbon is bonded covalently to only three others. These sheets are held together by much weaker van der Waals forces, and this discrepancy translates to big macroscopic differences.[55]

text: Twinning is the intergrowth of two or more crystal of a single mineral species. The geometry of the twinning is controlled by the mineral's symmetry. As a result, there are several types of twins, including contact twins, reticulated twins, geniculated twins, penetration twins, cyclic twins, and polysynthetic twins. Contact, or simple twins, consist of two crystals joined at a plane; this type of twinning is common in spinel. Reticulated twins, common in rutile, are interlocking crystals resembling netting. Geniculated twins have a bend in the middle that is caused by start of the twin. Penetration twins consist of two single crystals that have grown into each other; examples of this twinning include cross-shaped staurolite twins and Carlsbad twinning in orthoclase. Cyclic twins are caused by repeated twinning around a rotation axis. It occurs around three, four, five, six, or eight-fold axes, and the corresponding patterns are called threelings, fourlings, fivelings, sixlings, and eightlings. Sixlings are common in aragonite. Polysynthetic twins are similar to cyclic twinning by the presence of repetitive twinning; however, instead of occurring around a rotational axis, it occurs along parallel planes, usually on a microscopic scale.[56][57]

text: Crystal habit refers to the overall shape of crystal. Several terms are used to describe this property. Common habits include acicular, which described needlelike crystals like in natrolite, bladed, dendritic (tree-pattern, common in native copper), equant, which is typical of garnet, prismatic (elongated in one direction), and tabular, which differs from bladed habit in that the former is platy whereas the latter has a defined elongation. Related to crystal form, the quality of crystal faces is diagnostic of some minerals, especially with a petrographic microscope. Euhedral crystals have a defined external shape, while anhedral crystals do not; those intermediate forms are termed subhedral.[58][59]

text: Hardness

text: The hardness of a mineral defines how much it can resist scratching. This physical property is controlled by the chemical composition and crystalline structure of a mineral. A mineral's hardness is not necessarily constant for all sides, which is a function of its structure; crystallographic weakness renders some directions softer than others.[60] An example of this property exists in kyanite, which has a Mohs hardness of 5½ parallel to [001] but 7 parallel to [100].[61]

text: The most common scale of measurement is the ordinal Mohs hardness scale. Defined by ten indicators, a mineral with a higher index scratches those below it. The scale ranges from talc, a phyllosilicate, to diamond, a carbon polymorph that is the hardest natural material. The scale is provided below:[60]

text:
Mohs hardness
Mineral
Chemical formula

1
Talc
Mg3Si4O10(OH)2

2
Gypsum
CaSO4·2H2O

3
Calcite
CaCO3

4
Fluorite
CaF2

5
Apatite
Ca5(PO4)3(OH,Cl,F)

6
Orthoclase
KAlSi3O8

7
Quartz
SiO2

8
Topaz
Al2SiO4(OH,F)2

9
Corundum
Al2O3

10
Diamond
C

text: Lustre and diaphaneity

text: Lustre indicates how light reflects from the mineral's surface, with regards to its quality and intensity. There are numerous qualitative terms used to describe this property, which are split into metallic and non-metallic categories. Metallic and sub-metallic minerals have high reflectivity like metal; examples of minerals with this lustre are galena and pyrite. Non-metallic lustres include: adamantine, such as in diamond; vitreous, which is a glassy lustre very common in silicate minerals; pearly, such as in talc and apophyllite, resinous, such as members of the garnet group, silky which common in fibrous minerals such as asbestiform chrysotile.[62]

text: The diaphaneity of a mineral describes the ability of light to pass through it. Transparent minerals do not diminish the intensity of light passing through it. An example of such a mineral is muscovite (potassium mica); some varieties are sufficiently clear to have been used for windows. Translucent minerals allow some light to pass, but less than those that are transparent. Jadeite and nephrite (mineral forms of jade are examples of minerals with this property). Minerals that do not allow light to pass are called opaque.[63][64]

text: The diaphaneity of a mineral depends on thickness of the sample. When a mineral is sufficiently thin (e.g., in a thin section for petrography), it may become transparent even if that property is not seen in hand sample. In contrast, some minerals, such as hematite or pyrite are opaque even in thin-section.[64]

text: Colour and streak

text: Colour is the most obvious property of a mineral, but it is often non-diagnostic.[65] It is caused by electromagnetic radiation interacting with electrons (except in the case of incandescence, which does not apply to minerals).[66] Two broad classes of elements (idiochromatic and allochromatic) are defined with regards to their contribution to a mineral's colour: Idiochromatic elements are essential to a mineral's composition; their contribution to a mineral's colour is diagnostic.[63][67] Examples of such minerals are malachite (green) and azurite (blue). In contrast, allochromatic elements in minerals are present in trace amounts as impurities. An example of such a mineral would be the ruby and sapphire varieties of the mineral corundum.[67] The colours of pseudochromatic minerals are the result of interference of light waves. Examples include labradorite and bornite.

text: In addition to simple body colour, minerals can have various other distinctive optical properties, such as play of colours, asterism, chatoyancy, iridescence, tarnish, and pleochroism. Several of these properties involve variability in colour. Play of colour, such as in opal, results in the sample reflecting different colours as it is turned, while pleochroism describes the change in colour as light passes through a mineral in a different orientation. Iridescence is a variety of the play of colours where light scatters off a coating on the surface of crystal, cleavage planes, or off layers having minor gradations in chemistry.[68] In contrast, the play of colours in opal is caused by light refracting from ordered microscopic silica spheres within its physical structure.[69] Chatoyancy ("cat's eye") is the wavy banding of colour that is observed as the sample is rotated; asterism, a variety of chatoyancy, gives the appearance of a star on the mineral grain. The latter property is particularly common in gem-quality corundum.[68][69]

text: The streak of a mineral refers to the colour of a mineral in powdered form, which may or may not be identical to its body colour.[67] The most common way of testing this property is done with a streak plate, which is made out of porcelain and coloured either white or black. The streak of a mineral is independent of trace elements[63] or any weathering surface.[67] A common example of this property is illustrated with hematite, which is coloured black, silver, or red in hand sample, but has a cherry-red[63] to reddish-brown streak.[67] Streak is more often distinctive for metallic minerals, in contrast to non-metallic minerals whose body colour is created by allochromatic elements.[63] Streak testing is constrained by the hardness of the mineral, as those harder than 7 powder the streak plate instead.[67]

text: Cleavage, parting, fracture, and tenacity

text: By definition, minerals have a characteristic atomic arrangement. Weakness in this crystalline structure causes planes of weakness, and the breakage of a mineral along such planes is termed cleavage. The quality of cleavage can be described based on how cleanly and easily the mineral breaks; common descriptors, in order of decreasing quality, are "perfect", "good", "distinct", and "poor". In particularly transparent mineral, or in thin-section, cleavage can be seen a series of parallel lines marking the planar surfaces when viewed at a side. Cleavage is not a universal property among minerals; for example, quartz, consisting of extensively interconnected silica tetrahedra, does not have a crystallographic weakness which would allow it to cleave. In contrast, micas, which have perfect basal cleavage, consist of sheets of silica tetrahedra which are very weakly held together.[70][71]

text: As cleavage is a function of crystallography, there are a variety of cleavage types. Cleavage occurs typically in either one, two, three, four, or six directions. Basal cleavage in one direction is a distinctive property of the micas. Two-directional cleavage is described as prismatic, and occurs in minerals such as the amphiboles and pyroxenes. Minerals such as galena or halite have cubic (or isometric) cleavage in three directions, at 90°; when three directions of cleavage are present, but not at 90°, such as in calcite or rhodochrosite, it is termed rhombohedral cleavage. Octahedral cleavage (four directions) is present in fluorite and diamond, and sphalerite has six-directional dodecahedral cleavage.[70][71]

text: Minerals with many cleavages might not break equally well in all of the directions; for example, calcite has good cleavage in three direction, but gypsum has perfect cleavage in one direction, and poor cleavage in two other directions. Angles between cleavage planes vary between minerals. For example, as the amphiboles are double-chain silicates and the pyroxenes are single-chain silicates, the angle between their cleavage planes is different. The pyroxenes cleave in two directions at approximately 90°, whereas the amphiboles distinctively cleave in two directions separated by approximately 120° and 60°. The cleavage angles can be measured with a contact goniometer, which is similar to a protractor.[70][71]

text: Parting, sometimes called "false cleavage", is similar in appearance to cleavage but is instead produced by structural defects in the mineral as opposed to systematic weakness. Parting varies from crystal to crystal of a mineral, whereas all crystals of a given mineral will cleave if the atomic structure allows for that property. In general, parting is caused by some stress applied to a crystal. The sources of the stresses include deformation (e.g. an increase in pressure), exsolution, or twinning. Minerals that often display parting include the pyroxenes, hematite, magnetite, and corundum.[70][72]

text: When a mineral is broken in a direction that does not correspond to a plane of cleavage, it is termed to have been fractured. There are several types of uneven fracture. The classic example is conchoidal fracture, like that of quartz; rounded surfaces are created, which are marked by smooth curved lines. This type of fracture occurs only in very homogeneous minerals. Other types of fracture are fibrous, splintery, and hackly. The latter describes a break along a rough, jagged surface; an example of this property is found in native copper.[73]

text: Tenacity is related to both cleavage and fracture. Whereas fracture and cleavage describes the surfaces that are created when a mineral is broken, tenacity describes how resistant a mineral is to such breaking. Minerals can be described as brittle, ductile, malleable, sectile, flexible, or elastic.[74]

text: Specific gravity

text: Specific gravity numerically describes the density of a mineral. The dimensions of density are mass divided by volume with units: kg/m3 or g/cm3. Specific gravity measures how much water a mineral sample displaces. Defined as the quotient of the mass of the sample and difference between the weight of the sample in air and its corresponding weight in water, specific gravity is a unitless ratio. Among most minerals, this property is not diagnostic. Rock forming minerals – typically silicates or occasionally carbonates – have a specific gravity of 2.5–3.5.[75]

text: High specific gravity is a diagnostic property of a mineral. A variation in chemistry (and consequently, mineral class) correlates to a change in specific gravity. Among more common minerals, oxides and sulfides tend to have a higher specific gravity as they include elements with higher atomic mass. A generalization is that minerals with metallic or adamantine lustre tend to have higher specific gravities than those having a non-metallic to dull lustre. For example, hematite, Fe2O3, has a specific gravity of 5.26[76] while galena, PbS, has a specific gravity of 7.2–7.6,[77] which is a result of their high iron and lead content, respectively. A very high specific gravity becomes very pronounced in native metals; kamacite, an iron-nickel alloy common in iron meteorites has a specific gravity of 7.9,[78] and gold has an observed specific gravity between 15 and 19.3.[75][79]

text: Other properties

text: Other properties can be used to diagnose minerals. These are less general, and apply to specific minerals.

text: Dropping dilute acid (often 10% HCl) aids in distinguishing carbonates from other mineral classes. The acid reacts with the carbonate ([CO3]2−) group, which causes the affected area to effervesce, giving off carbon dioxide gas. This test can be further expanded to test the mineral in its original crystal form or powdered. An example of this test is done when distinguish calcite from dolomite, especially within rocks (limestone and dolostone respectively). Calcite immediately effervesces in acid, whereas acid must be applied to powdered dolomite (often to a scratched surface in a rock), for it to effervesce.[80] Zeolite minerals will not effervesce in acid; instead, they become frosted after 5–10 minutes, and if left in acid for a day, they dissolve or become a silica gel.[81]

text: When tested, magnetism is a very conspicuous property of minerals. Among common minerals, magnetite exhibits this property strongly, and it is also present, albeit not as strongly, in pyrrhotite and ilmenite.[80] Some minerals exhibit electrical properties – for example, quartz is piezoelectric – but electrical properties are rarely used as diagnostic criteria for minerals because of incomplete data and natural variation.[82]

text: Minerals can also be tested for taste or smell. Halite, NaCl, is table salt; its potassium-bearing counterpart, sylvite, has a pronounced bitter taste. Sulfides have a characteristic smell, especially as samples are fractured, reacting, or powdered.[80]

text: Radioactivity is a rare property; minerals may be composed of radioactive elements. They could be a defining constituent, such as uranium in uraninite, autunite, and carnotite, or as trace impurities. In the latter case, the decay of a radioactive element damages the mineral crystal; the result, termed a radioactive halo or pleochroic halo, is observable by various techniques, such as thin-section petrography.[80]

text: Classification

text: As the composition of the Earth's crust is dominated by silicon and oxygen, silicate elements are by far the most important class of minerals in terms of rock formation and diversity. However, non-silicate minerals are of great economic importance, especially as ores.[83][84]

text: Non-silicate minerals are subdivided into several other classes by their dominant chemistry, which included native elements, sulfides, halides, oxides and hydroxides, carbonates and nitrates, borates, sulfates, phosphates, and organic compounds. Most non-silicate mineral species are rare (constituting in total 8% of the Earth's crust), although some are relatively common, such as calcite, pyrite, magnetite, and hematite. There are two major structural styles observed in non-silicates: close-packing and silicate-like linked tetrahedra. The close-packed structures, which is a way to densely pack atoms while minimizing interstitial space. Hexagonal close-packing involves stacking layers where every other layer is the same ("ababab"), whereas cubic close-packing involves stacking groups of three layers ("abcabcabc"). Analogues to linked silica tetrahedra include SO4 (sulfate), PO4 (phosphate), AsO4 (arsenate), and VO4 (vanadate). The non-silicates have great economic importance, as they concentrate elements more than the silicate minerals do.[85]

text: The largest grouping of minerals by far are the silicates; most rocks are composed of greater than 95% silicate minerals, and over 90% of the Earth's crust is composed of these minerals.[86] The two main constituents of silicates are silicon and oxygen, which are the two most abundant elements in the Earth's crust. Other common elements in silicate minerals correspond to other common elements in the Earth's crust, such aluminium, magnesium, iron, calcium, sodium, and potassium.[87] Some important rock-forming silicates include the feldspars, quartz, olivines, pyroxenes, amphiboles, garnets, and micas.

text: Silicates

text: The base of unit of a silicate mineral is the [SiO4]4− tetrahedron. In the vast majority of cases, silicon is in four-fold or tetrahedral coordination with oxygen. In very high-pressure situations, silicon will be six-fold or octahedral coordination, such as in the perovskite structure or the quartz polymorph stishovite (SiO2). In the latter case, the mineral no longer has a silicate structure, but that of rutile (TiO2), and its associated group, which are simple oxides. These silica tetrahedra are then polymerized to some degree to create various structures, such as one-dimensional chains, two-dimensional sheets, and three-dimensional frameworks. The basic silicate mineral where no polymerization of the tetrahedra has occurred requires other elements to balance out the base 4- charge. In other silicate structures, different combinations of elements are required to balance out the resultant negative charge. It is common for the Si4+ to be substituted by Al3+ because of similarity in ionic radius and charge; in those case, the [AlO4]5− tetrahedra form the same structures as do the unsubstituted tetrahedra, but their charge-balancing requirements are different.[88]

text: The degree of polymerization can be described by both the structure formed and how many tetrahedral corners (or coordinating oxygens) are shared (for aluminium and silicon in tetrahedral sites).[89] Orthosilicates (or nesosilicates) have no linking of polyhedra, thus tetrahedra share no corners. Disilicates (or sorosilicates) have two tetrahedra sharing one oxygen atom. Inosilicates are chain silicates; single-chain silicates have two shared corners, whereas double-chain silicates have two or three shared corners. In phyllosilicates, a sheet structure is formed which requires three shared oxygens; in the case of double-chain silicates, some tetrahedra must share two corners instead of three as otherwise a sheet structure would result. Framework silicates, or tectosilicates, have tetrahedra that share all four corners. The ring silicates, or cyclosilicates, only need tetrahedra to share two corners to form the cyclical structure.[90]

text: The silicate subclasses are described below in order of decreasing polymerization.

text: Tectosilicates

text: Tectosilicates, also known as framework silicates, have the highest degree of polymerization. With all corners of a tetrahedra shared, the silicon:oxygen ratio becomes 1:2. Examples are quartz, the feldspars, feldspathoids, and the zeolites. Framework silicates tend to be particularly chemically stable as a result of strong covalent bonds.[91]

text: Forming 12% of the Earth's crust, quartz (SiO2) is the most abundant mineral species. It is characterized by its high chemical and physical resistivity. Quartz has several polymorphs, including tridymite and cristobalite at high temperatures, high-pressure coesite, and ultra-high pressure stishovite. The latter mineral can only be formed on Earth by meteorite impacts, and its structure has been composed so much that it had changed from a silicate structure to that of rutile (TiO2). The silica polymorph that is most stable at the Earth's surface is α-quartz. Its counterpart, β-quartz, is present only at high temperatures and pressures (changes to α-quartz below 573 °C at 1 bar). These two polymorphs differ by a "kinking" of bonds; this change in structure gives β-quartz greater symmetry than α-quartz, and they are thus also called high quartz (β) and low quartz (α).[86][92]

text: Feldspars are the most abundant group in the Earth's crust, at about 50%. In the feldspars, Al3+ substitutes for Si4+, which creates a charge imbalance that must be accounted for by the addition of cations. The base structure becomes either [AlSi3O8]− or [Al2Si2O8]2− There are 22 mineral species of feldspars, subdivided into two major subgroups – alkali and plagioclase – and two less common groups – celsian and banalsite. The alkali feldspars are most commonly in a series between potassium-rich orthoclase and sodium-rich albite; in the case of plagioclase, the most common series ranges from albite to calcium-rich anorthite. Crystal twinning is common in feldspars, especially polysynthetic twins in plagioclase and Carlsbad twins in alkali feldspars. If the latter subgroup cools slowly from a melt, it forms exsolution lamellae because the two components – orthoclase and albite – are unstable in solid solution. Exsolution can be on a scale from microscopic to readily observable in hand-sample; perthitic texture forms when Na-rich feldspar exsolve in a K-rich host. The opposite texture (antiperthitic), where K-rich feldspar exsolves in a Na-rich host, is very rare.[93]

text: Feldspathoids are structurally similar to feldspar, but differ in that they form in Si-deficient conditions which allows for further substitution by Al3+. As a result, feldsapthoids cannot be associated with quartz. A common example of a feldsapthoid is nepheline ((Na, K)AlSiO4); compared to alkali feldspar, nepheline has an Al2O3:SiO2 ratio of 1:2, as opposed to 1:6 in the feldspar.[94] Zeolites often have distinctive crystal habits, occurring in needles, plates, or blocky masses. They form in the presence of water at low temperatures and pressures, and have channels and voids in their structure. Zeolites have several industrial applications, especially in waste water treatment.[95]

text: Phyllosilicates

text: Phyllosilicates consist of sheets of polymerized tetrahedra. They are bound at three oxygen sites, which gives a characteristic silicon:oxygen ratio of 2:5. Important examples include the mica, chlorite, and the kaolinite-serpentine groups. The sheets are weakly bound by van der Waals forces or hydrogen bonds, which causes a crystallographic weakness, in turn leading to a prominent basal cleavage among the phyllosilicates.[96] In addition to the tetrahedra, phyllosilicates have a sheet of octahedra (elements in six-fold coordination by oxygen) that balanced out the basic tetrahedra, which have a negative charge (e.g. [Si4O10]4−) These tetrahedra (T) and octahedra (O) sheets are stacked in a variety of combinations to create phyllosilicate groups. Within an octahedral sheet, there are three octahedral sites in a unit structure; however, not all of the sites may be occupied. In that case, the mineral is termed dioctahedral, whereas in other case it is termed trioctahedral.[97]

text: The kaolinite-serpentine group consists of T-O stacks (the 1:1 clay minerals); their hardness ranges from 2 to 4, as the sheets are held by hydrogen bonds. The 2:1 clay minerals (pyrophyllite-talc) consist of T-O-T stacks, but they are softer (hardness from 1 to 2), as they are instead held together by van der Waals forces. These two groups of minerals are subgrouped by octahedral occupation; specifically, kaolinite and pyrophyllite are dioctahedral whereas serpentine and talc trioctahedral.[98]

text: Micas are also T-O-T-stacked phyllosilicates, but differ from the other T-O-T and T-O-stacked subclass members in that they incorporate aluminium into the tetrahedral sheets (clay minerals have Al3+ in octahedral sites). Common examples of micas are muscovite, and the biotite series. The chlorite group is related to mica group, but a brucite-like (Mg(OH)2) layer between the T-O-T stacks.[99]

text: Because of their chemical structure, phyllosilicates typically have flexible, elastic, transparent layers that are electrical insulators and can be split into very thin flakes. Micas can be used in electronics as insulators, in construction, as optical filler, or even cosmetics. Chrysotile, a species of serpentine, is the most common mineral species in industrial asbestos, as it is less dangerous in terms of health than the amphibole asbestos.[100]

text: Inosilicates

text: Inosilicates consist of tetrahedra repeatedly bonded in chains. These chains can be single, where a tetrahedron is bound to two others to form a continuous chain; alternatively, two chains can be merged to create double-chain silicates. Single-chain silicates have a silicon:oxygen ratio of 1:3 (e.g. [Si2O6]4−), whereas the double-chain variety has a ratio of 4:11, e.g. [Si8O22]12−. Inosilicates contain two important rock-forming mineral groups; single-chain silicates are most commonly pyroxenes, while double-chain silicates are often amphiboles.[101] Higher-order chains exist (e.g. three-member, four-member, five-member chains, etc.) but they are rare.[102]

text: The pyroxene group consists of 21 mineral species.[103] Pyroxenes have a general structure formula of XY(Si2O6), where X is an octahedral site, while Y can vary in coordination number from six to eight. Most varieties of pyroxene consist of permutations of Ca2+, Fe2+ and Mg2+ to balance the negative charge on the backbone. Pyroxenes are common in the Earth's crust (about 10%) and are a key constituent of mafic igneous rocks.[104]

text: Amphiboles have great variability in chemistry, described variously as a "mineralogical garbage can" or a "mineralogical shark swimming a sea of elements". The backbone of the amphiboles is the [Si8O22]12−; it is balanced by cations in three possible positions, although the third position is not always used, and one element can occupy both remaining ones. Finally, the amphiboles are usually hydrated, that is, they have a hydroxyl group ([OH]−), although it can be replaced by a fluoride, a chloride, or an oxide ion.[105] Because of the variable chemistry, there are over 80 species of amphibole, although variations, as in the pyroxenes, most commonly involve mixtures of Ca2+, Fe2+ and Mg2+.[103] Several amphibole mineral species can have an asbestiform crystal habit. These asbestos minerals form long, thin, flexible, and strong fibres, which are electrical insulators, chemically inert and heat-resistant; as such, they have several applications, especially in construction materials. However, asbestos are known carcinogens, and cause various other illnesses, such as asbestosis; amphibole asbestos (anthophyllite, tremolite, actinolite, grunerite, and riebeckite) are considered more dangerous than chrysotile serpentine asbestos.[106]

text: Cyclosilicates

text: Cyclosilicates, or ring silicates, have a ratio of silicon to oxygen of 1:3. Six-member rings are most common, with a base structure of [Si6O18]12−; examples include the tourmaline group and beryl. Other ring structures exist, with 3, 4, 8, 9, 12 having been described.[107] Cyclosilicates tend to be strong, with elongated, striated crystals.[108]

text: Tourmalines have a very complex chemistry that can be described by a general formula XY3Z6(BO3)3T6O18V3W. The T6O18 is the basic ring structure, where T is usually Si4+, but substitutable by Al3+ or B3+. Tourmalines can be subgrouped by the occupancy of the X site, and from there further subdivided by the chemistry of the W site. The Y and Z sites can accommodate a variety of cations, especially various transition metals; this variability in structural transition metal content gives the tourmaline group greater variability in colour. Other cyclosilicates include beryl, Al2Be3Si6O18, whose varieties include the gemstones emerald (green) and aquamarine (bluish). Cordierite is structurally similar to beryl, and is a common metamorphic mineral.[109]

text: Sorosilicates

text: Sorosilicates, also termed disilicates, have tetrahedron-tetrahedron bonding at one oxygen, which results in a 2:7 ratio of silicon to oxygen. The resultant common structural element is the [Si2O7]6− group. The most common disilicates by far are members of the epidote group. Epidotes are found in variety of geologic settings, ranging from mid-ocean ridge to granites to metapelites. Epidotes are built around the structure [(SiO4)(Si2O7)]10− structure; for example, the mineral species epidote has calcium, aluminium, and ferric iron to charge balance: Ca2Al2(Fe3+, Al)(SiO4)(Si2O7)O(OH). The presence of iron as Fe3+ and Fe2+ helps understand oxygen fugacity, which in turn is a significant factor in petrogenesis.[110]

text: Other examples of sorosilicates include lawsonite, a metamorphic mineral forming in the blueschist facies (subduction zone setting with low temperature and high pressure), vesuvianite, which takes up a significant amount of calcium in its chemical structure.[110][111]

text: Orthosilicates

text: Orthosilicates consist of isolated tetrahedra that are charge-balanced by other cations.[112] Also termed nesosilicates, this type of silicate has a silicon:oxygen ratio of 1:4 (e.g. SiO4). Typical orthosilicates tend to form blocky equant crystals, and are fairly hard.[113] Several rock-forming minerals are part of this subclass, such as the aluminosilicates, the olivine group, and the garnet group.

text: The aluminosilicates –bkyanite, andalusite, and sillimanite, all Al2SiO5 – are structurally composed of one [SiO4]4− tetrahedron, and one Al3+ in octahedral coordination. The remaining Al3+ can be in six-fold coordination (kyanite), five-fold (andalusite) or four-fold (sillimanite); which mineral forms in a given environment is depend on pressure and temperature conditions. In the olivine structure, the main olivine series of (Mg, Fe)2SiO4 consist of magnesium-rich forsterite and iron-rich fayalite. Both iron and magnesium are in octahedral by oxygen. Other mineral species having this structure exist, such as tephroite, Mn2SiO4.[114] The garnet group has a general formula of X3Y2(SiO4)3, where X is a large eight-fold coordinated cation, and Y is a smaller six-fold coordinated cation. There are six ideal endmembers of garnet, split into two group. The pyralspite garnets have Al3+ in the Y position: pyrope (Mg3Al2(SiO4)3), almandine (Fe3Al2(SiO4)3), and spessartine (Mn3Al2(SiO4)3). The ugrandite garnets have Ca2+ in the X position: uvarovite (Ca3Cr2(SiO4)3), grossular (Ca3Al2(SiO4)3) and andradite (Ca3Fe2(SiO4)3). While there are two subgroups of garnet, solid solutions exist between all six end-members.[112]

text: Other orthosilicates include zircon, staurolite, and topaz. Zircon (ZrSiO4) is useful in geochronology as the Zr4+ can be substituted by U6+; furthermore, because of its very resistant structure, it is difficult to reset it as a chronometer. Staurolite is a common metamorphic intermediate-grade index mineral. It has a particularly complicated crystal structure that was only fully described in 1986. Topaz (Al2SiO4(F, OH)2, often found in granitic pegmatites associated with tourmaline, is a common gemstone mineral.[115]

text: Non-silicates

text: Native elements

text: Native elements are those that are not chemically bonded to other elements. This mineral group includes native metals, semi-metals, and non-metals, and various alloys and solid solutions. The metals are held together by metallic bonding, which confers distinctive physical properties such as their shiny metallic lustre, ductility and malleability, and electrical conductivity. Native elements are subdivided into groups by their structure or chemical attributes.

text: The gold group, with a cubic close-packed structure, includes metals such as gold, silver, and copper. The platinum group is similar in structure to the gold group. The iron-nickel group is characterized by several iron-nickel alloy species. Two examples are kamacite and taenite, which are found in iron meteorites; these species differ by the amount of Ni in the alloy; kamacite has less than 5–7% nickel and is a variety of native iron, whereas the nickel content of taenite ranges from 7–37%. Arsenic group minerals consist of semi-metals, which have only some metallic; for example, they lack the malleability of metals. Native carbon occurs in two allotropes, graphite and diamond; the latter forms at very high pressure in the mantle, which gives it a much stronger structure than graphite.[116]

text: Sulfides

text: The sulfide minerals are chemical compounds of one or more metals or semimetals with a sulfur; tellurium, arsenic, or selenium can substitute for the sulfur. Sulfides tend to be soft, brittle minerals with a high specific gravity. Many powdered sulfides, such as pyrite, have a sulfurous smell when powdered. Sulfides are susceptible to weathering, and many readily dissolve in water; these dissolved minerals can be later redeposited, which creates enriched secondary ore deposits.[117] Sulfides are classified by the ratio of the metal or semimetal to the sulfur, such as M:S equal to 2:1, or 1:1.[118] Many sulfide minerals are economically important as metal ores; examples include sphalerite (ZnS), an ore of zinc, galena (PbS), an ore of lead, cinnabar (HgS), an ore of mercury, and molybdenite (MoS2, an ore of molybdenum.[119] Pyrite (FeS2), is the most commonly occurring sulfide, and can be found in most geological environments. It is not, however, an ore of iron, but can be instead oxidized to produce sulfuric acid.[120] Related to the sulfides are the rare sulfosalts, in which a metallic element is bonded to sulfur and a semimetal such as antimony, arsenic, or bismuth. Like the sulfides, sulfosalts are typically soft, heavy, and brittle minerals.[121]

text: Oxides

text: Oxide minerals are divided into three categories: simple oxides, hydroxides, and multiple oxides. Simple oxides are characterized by O2− as the main anion and primarily ionic bonding. They can be further subdivided by the ratio of oxygen to the cations. The periclase group consists of minerals with a 1:1 ratio. Oxides with a 2:1 ratio include cuprite (Cu2O) and water ice. Corundum group minerals have a 2:3 ratio, and includes minerals such as corundum (Al2O3), and hematite (Fe2O3). Rutile group minerals have a ratio of 1:2; the eponymous species, rutile (TiO2) is the chief ore of titanium; other examples include cassiterite (SnO2; ore of tin), and pyrolusite (MnO2; ore of manganese).[122][123] In hydroxides, the dominant anion is the hydroxyl ion, OH−. Bauxites are the chief aluminium ore, and are a heterogeneous mixture of the hydroxide minerals diaspore, gibbsite, and bohmite; they form in areas with a very high rate of chemical weathering (mainly tropical conditions).[124] Finally, multiple oxides are compounds of two metals with oxygen. A major group within this class are the spinels, with a general formula of X2+Y3+2O4. Examples of species include spinel (MgAl2O4), chromite (FeCr2O4), and magnetite (Fe3O4). The latter is readily distinguishable by its strong magnetism, which occurs as it has iron in two oxidation states (Fe2+Fe3+2O4), which makes it a multiple oxide instead of a single oxide.[125]

text: Halides

text: The halide minerals are compounds where a halogen (fluorine, chlorine, iodine, and bromine) is the main anion. These minerals tend to be soft, weak, brittle, and water-soluble. Common examples of halides include halite (NaCl, table salt), sylvite (KCl), fluorite (CaF2). Halite and sylvite commonly form as evaporites, and can be dominant minerals in chemical sedimentary rocks. Cryolite, Na3AlF6, is a key mineral in the extraction of aluminium from bauxites; however, as the only significant occurrence at Ivittuut, Greenland, in a granitic pegmatite, was depleted, synthetic cryolite can be made from fluorite.[126]

text: Carbonates

text: The carbonate minerals are those were the main anionic group is carbonate, [CO3]2−. Carbonates tend to be brittle, many have rhombohedral cleavage, and all react with acid.[127] Due to the last characteristic, field geologists often carry dilute hydrochloric acid to distinguish carbonates from non-carbonates. The reaction of acid with carbonates, most commonly found as the polymorph calcite and aragonite (CaCO3), relates to the dissolution and precipitation of the mineral, which is a key in the formation of limestone caves, features within them such as stalactite and stalagmites, and karst landforms. Carbonates are most often formed as biogenic or chemical sediments in marine environments. The carbonate group is structurally a triangle, where a central C4+ cation is surrounded by three O2− anions; different groups of minerals form from different arrangements of these triangles.[128] The most common carbonate mineral is calcite, and is the primary constituent of sedimentary limestone and metamorphic marble. Calcite, CaCO3, can have a high magnesium impurity; under high-Mg conditions, its polymorph aragonite will form instead; the marine geochemistry in this regard can be described as an aragonite or calcite sea, depending on which mineral preferentially forms. Dolomite is a double carbonate, with the formula CaMg(CO3)2. Secondary dolomitization of limestone is common, where calcite or aragonite are converted to dolomite; this reaction increases pore space (the unit cell volume of dolomite is 88% that of calcite), which can create a reservoir for oil and gas. These two minerals species are members of eponymous mineral groups: the calcite group includes carbonates with the general formula XCO3, and the dolomite group constitutes minerals with general formula XY(CO3)2.[129]

text: Sulfates

text: The sulfate minerals all contain the sulfate anion, [SO4]2−. They tend to be transparent to translucent, soft, and many are fragile.[130] Sulfate minerals commonly form as evaporites, where they precipitate out of evaporating saline waters; alternative, sulfates can also be found in hydrothermal vein systems associated with sulfides,[131] or as oxidation products of sulfides.[132] Sulfates can be subdivided into anhydrous and hydrous minerals. The most common hydrous sulfate by far is gypsum, CaSO4⋅2H2O. It forms as an evaporite, and is associated with other evaporites such as calcite and halite; if it incorporates sand grains as it crystallizes, gypsum can form desert roses. Gypsum has very low thermal conductivity and maintains a low temperature when heated as it loses that heat by dehydrating; as such, gypsum is used as an insulator in materials such as plaster and drywall. The anhydrous equivalent of gypsum is anhydrite; it can form directly from seawater in highly arid conditions. The barite group has the general formula XSO4, where the X is a large 12-coordinated cation. Examples include barite (BaSO4), celestine (SrSO4), and anglesite (PbSO4); anhydrite is not part of the barite group, as the smaller Ca2+ is only in eight-fold coordination.[133]

text: Phosphates

text: The phosphate minerals are characterized by the tetrahedral [PO4]3− unit, although the structure can be generalized, and phosphorus is replaced by antimony, arsenic, or vanadium. The most common phosphate is the apatite group; common species within this group are fluorapatite (Ca5(PO4)3F), chlorapatite (Ca5(PO4)3Cl) and hydroxylapatite (Ca5(PO4)3(OH)). Minerals in this group are the main crystalline constituents of teeth and bones in vertebrates. The relatively abundant monazite group has a general structure of ATO4, where T is phosphorus or arsenic, and A is often a rare-earth element (REE). Monazite is important in two ways: first, as a REE "sink", it can sufficiently concentrate these elements to become an ore; secondly, monazite group elements can incorporate relatively large amounts of uranium and thorium, which can be used in monazite geochronology to date the rock based on the decay of the U and Th to lead.[134]

text: Organic minerals

text: The Strunz classification includes a class for organic minerals. These rare compounds contain organic carbon, but can be formed by a geologic process. For example, whewellite, CaC2O4⋅H2O is an oxalate that can be deposited in hydrothermal ore veins. While hydrated calcium oxalate can be found in coal seams and other sedimentary deposits involving organic matter, the hydrothermal occurrence is not considered to be related to biological activity.[84]

text: Astrobiology

text: It has been suggested that biominerals could be important indicators of extraterrestrial life and thus could play an important role in the search for past or present life on the planet Mars. Furthermore, organic components (biosignatures) that are often associated with biominerals are believed to play crucial roles in both pre-biotic and biotic reactions.[135]

text: On January 24, 2014, NASA reported that current studies by the Curiosity and Opportunity rovers on Mars will now be searching for evidence of ancient life, including a biosphere based on autotrophic, chemotrophic and/or chemolithoautotrophic microorganisms, as well as ancient water, including fluvio-lacustrine environments (plains related to ancient rivers or lakes) that may have been habitable.[136][137][138][139] The search for evidence of habitability, taphonomy (related to fossils), and organic carbon on the planet Mars is now a primary NASA objective.[136][137]


document_title: List of Ryder Cup matches

question_text: when's the last time the united states won the ryder cup

question_tokens: when 's the last time the united states won the ryder cup

text: List of Ryder Cup matches

text: History[edit]

text: The first Ryder Cup match was contested in June 1927. The competition held at Worcester Country Club was won 9½–2½ by the United States. British captain Ted Ray cited the Americans' "superior putting" as the reason for their victory.[7] Great Britain improved for the 1929 competition, winning 7–5 at Moortown Golf Club.[8] However, they were unable to replicate this performance in 1931. In 100 degree heat and missing a number of their best players, they were unable to match the Americans at the Scioto Country Club and lost 9–3.[9] The 1933 contest at the Southport and Ainsdale Golf Club was a closer affair than previous matches. It came down to the final match between Syd Easterbrook and Denny Shute. The American Shute had a putt to win the competition, but missed two in succession leaving Easterbrook with a putt to win the contest, which he made to secure a 6½–5½ victory for the British team.[10] The United States regained the Cup in 1935, when they beat Great Britain 9–3 at Ridgewood Country Club.[11] They became the first team to win the competition outside of their own country in 1937 when they beat the British team 8–4 at Southport and Ainsdale Golf Club.[12]

text: The advent of the Second World War meant the Ryder Cup was not contested again until 1947 at Portland Golf Club. The United States dominated the match in wet conditions, as Great Britain scored one point in an 11–1 defeat.[13] The 1949 match was closer than the previous contest. Great Britain went into the final day with a 3–1 lead, but they were unable to secure the three and a half points they needed to win and lost 7–5.[14] The 1951 contest at Pinehurst Resort, was again won by the United States. Such was the dominance in their 9½–2½ victory, that only two of the twelve matches reached the 18th hole.[15] Before the 1953 contest Great Britain were given a boost when American Ben Hogan decided not to participate. He had won three of the four men's major golf championships during the year and his absence gave them optimism. However, they were unable to beat the United States; mistakes at the end of their singles matches by Peter Alliss and Bernard Hunt cost Great Britain as they lost 6½–5½.[16] Despite recording their best points total in matches held in the United States, Great Britain were again defeated in 1955. The United States won 8–4 to extend their winning streak to 21 years.[17]

text: The 1957 contest saw Great Britain regain the Cup for the first time since 1933. They were 3–1 down after the first round of matches, but victory in five out of the seven singles matches made the difference as they won 7½–4½.[18] The United States regained the Ryder Cup in 1959 beating Great Britain 8½–3½. The match was the last to be contested over 36 holes of foursomes and singles matches. The format changed to two 18 hole sets of foursomes and singles in 1961, doubling the number of points available from 12 to 24.[19][20] The change in format did not affect the trend of American dominance as they won 14½–9½ at Royal Lytham & St Annes Golf Club.[21] Two sets of four balls were introduced in 1963, increasing the number of points available to 32.[22] Again, the changes made little difference to the outcome as the United States won 23–9 at East Lake Golf Club. British player Henry Cotton summed up the display from the Americans, stating: "We have been outclassed."[23] The 1965 match at Royal Birkdale Golf Club started well for Great Britain, as they were trailing the United States 9–7 going into the singles matches. But the Americans proved too strong, winning the majority of the matches to win the contest 19½–12½.[24]

text: The 1967 match continued the trend of American victories, as the United States won 23½–8½ at Champions Golf Club.[25] Unlike in previous years, the 1969 match was much closer. The match came down to the last hole of the final singles match between American Jack Nicklaus and British golfer Tony Jacklin. Nicklaus made his putt, which left Jacklin with a putt to tie the match. Despite this, Nicklaus conceded the putt, picking up Jacklin's ball marker. As a result their match was tied, as was the contest at 16–16.[26] The United States won again in 1971, beating Great Britain 18½–13½.[27] The 1973 match was the first held in Scotland at Muirfield.[28] The outcome remained the same as Great Britain lost 19–13.[29] The 1975 match at Laurel Valley Golf Club was similar with the United States winning 21–11.[30] The format changed again in 1977, as matches were reduced by nearly a third leaving 20 points available. The changed requested by Great Britain & Ireland did little to change the outcome, as the United States won 12½–7½.[31] Golfers from continental Europe were allowed to compete for the first time in 1979. There was another change to the format, the first two days now consisted of eight foursomes and fourballs, with twelve singles matches on the final day. Again, the changes had little effect on the outcome as the United States won 17–11.[32]

text: The 1981 match was originally scheduled to take place at The Belfry, but construction of the course was not completed on time and Walton Heath Golf Club was used instead. The United States, containing a team that had won 36 major championships between them, dominated the match winning 18½–9½.[33] The 1983 match at PGA National Golf Club was the closest in recent years. After the first two days the match was tied at 8–8. Europe fell short in the singles match, winning four out of the twelve matches and lost the contest 14½–13½.[34] The 1985 match held at the now completed Belfry, saw Europe win the trophy for the first time in 28 years. Leading 9–7 going into the final day, they won six singles matches to secure a 16½–11½ victory.[35] Europe retained the Ryder Cup in 1987, beating the United States 15–13 at Muirfield Village, to win in the United States for the first time.[36] The 1989 match was only the second time the contest ended in a tie. Europe were in commanding position when José Maria Cañizares won his singles match, but defeat in the last four matches meant the match finished 14–14.[37] The 1991 match at Kiawah Island Golf Resort, known as the "War on the Shore", saw the United States regain the Cup. The scores were tied at 8–8 going into the final day and the match came down to the last singles match between Europe's Bernhard Langer and American golfer Hale Irwin. Langer missed a 6 feet (1.8 m) putt at the last hole, which meant the United States won 14½–13½.[38] The United States retained the Cup in 1993, winning 15–13 at The Belfry.[39] Europe regained the trophy in 1995, defeating the United States 14½–13½ at Oak Hill Country Club.[40]

text: The Ryder Cup was played outside of the British Isles for the first time in 1997, as Valderrama Golf Club in Spain hosted the contest. Despite taking a five-point lead into the final day, Europe needed the half point Colin Montgomerie secured in his tied singles match with Scott Hoch to win 14½–13½.[41] The 1999 match was the third time in succession the contest had been won by a single point, but this time it was the United States who won 14½–13½.[42] This was not without controversy, as Europe were unhappy with the celebrations by the American team after a putt by Justin Leonard, while European golfer José María Olazábal still had a chance of holing his putt.[43] The Ryder Cup was scheduled to be played in 2001, but two weeks before the competition was scheduled to take place the September 11 attacks occurred. The United States fearing for their safety requested the match be played a year later in 2002.[44] When the match was played, Europe won 15½–12½ to regain the Cup.[45] They retained the Cup in 2004 when they won 18½–9½ at Oakland Hills Country Club, in what was the United States' heaviest defeat in the competition.[46] The result was repeated in 2006 at the K Club. Europe's 18½–9½ victory marked the first time they had won three matches in succession.[47] The United States regained the Ryder Cup in 2008, winning for the first time since 1999. They won the match when Jim Furyk beat Miguel Ángel Jiménez with four singles matches still ongoing, to win 16½–11½.[48] A tight contest in 2010 came down to the final singles match between European Graeme McDowell and American golfer Hunter Mahan. McDowell won his match with a hole to spare, to give Europe a 14½–13½ victory.[49] Europe recovered a 10–6 deficit on the last day in 2012, as they won eight of the twelve singles matches to win 14½–13½.[50]

text: United States vs Great Britain/Great Britain & Ireland (1927–1977)[edit]

text:
Key

Match was tied

tag: table

text: The "Year" column refers to the year the match was held, and wikilinks to the article about that match.

tag: ul

text:
Ryder Cup matches

Year

Winners

Score

Runners-up

Host country

Venue

GBI captain

United States captain

1927

 United States

9½–2½

 Great Britain

United States

Worcester Country Club, Massachusetts

 Ted Ray

Walter Hagen

1929

 Great Britain

7–5

 United States

England

Moortown Golf Club, Yorkshire

 George Duncan

Walter Hagen

1931

 United States

9–3

 Great Britain

United States

Scioto Country Club, Columbus, Ohio

 Charles Whitcombe

Walter Hagen

1933

 Great Britain

6½–5½

 United States

England

Southport and Ainsdale Golf Club, Lancashire

 John Henry Taylor

Walter Hagen

1935

 United States

9–3

 Great Britain

United States

Ridgewood Country Club, Paramus, New Jersey

 Charles Whitcombe

Walter Hagen

1937

 United States

8–4

 Great Britain

England

Southport and Ainsdale Golf Club, Lancashire

 Charles Whitcombe

Walter Hagen

1947

 United States

11–1

 Great Britain

United States

Portland Golf Club, Portland, Oregon

 Henry Cotton

Ben Hogan

1949

 United States

7–5

 Great Britain

England

Ganton Golf Club, Scarborough, Yorkshire

 Charles Whitcombe

Ben Hogan

1951

 United States

9½–2½

 Great Britain

United States

Pinehurst Resort Course No. 2, North Carolina

 Arthur Lacey

Sam Snead

1953

 United States

6½–5½

 Great Britain

England

Wentworth Club, Virginia Water, Surrey

 Henry Cotton

Lloyd Mangrum

1955

 United States

8–4

 Great Britain

United States

Thunderbird Country Club, Rancho Mirage, California

 Dai Rees

Chick Harbert

1957

 Great Britain

7½–4½

 United States

England

Lindrick Golf Club, West Riding of Yorkshire

 Dai Rees

Jack Burke, Jr.

1959

 United States

8½–3½

 Great Britain

United States

Eldorado Golf Club, Indian Wells, California

 Dai Rees

Sam Snead

1961

 United States

14½–9½

 Great Britain

England

Royal Lytham & St Annes Golf Club, Lytham St. Annes, Lancashire

 Dai Rees

Jerry Barber

1963

 United States

23–9

 Great Britain

United States

Atlanta Athletic Club, Atlanta, Georgia[a]

 John Fallon

Arnold Palmer

1965

 United States

19½–12½

 Great Britain

England

Royal Birkdale Golf Club, Southport, Lancashire

 Harry Weetman

Byron Nelson

1967

 United States

23½–8½

 Great Britain

United States

Champions Golf Club, Houston, Texas

 Dai Rees

Ben Hogan

1969

 United States [A]

16–16

 Great Britain

England

Royal Birkdale Golf Club, Southport, Lancashire

 Eric Brown

Sam Snead

1971

 United States

18½–13½

 Great Britain

United States

Old Warson Country Club, St. Louis, Missouri

 Eric Brown

Jay Hebert

1973

 United States

19–13

  Great Britain & Ireland

Scotland

Muirfield, Gullane, East Lothian

 Bernard Hunt

Jack Burke, Jr.

1975

 United States

21–11

  Great Britain & Ireland

United States

Laurel Valley Golf Club, Ligonier, Pennsylvania

 Bernard Hunt

Arnold Palmer

1977

 United States

12½–7½

  Great Britain & Ireland

England

Royal Lytham & St Annes Golf Club, Lytham St. Annes, Lancashire

 Brian Huggett

Dow Finsterwald

text: Jump up ^ This is not the current Atlanta Athletic Club site in the Atlanta suburb of Johns Creek, Georgia, but is instead the original AAC course that is now known as East Lake Golf Club.

tag: ol

text: United States vs Europe (1979–present)[edit]

text:
Key

Match was tied

text:
Ryder Cup matches

Year

Winners

Score

Runners-up

Host country

Venue

Europe captain

United States captain

1979

 United States

17–11

 Europe

United States

The Greenbrier, The Greenbrier Course, White Sulphur Springs, West Virginia

 John Jacobs

Billy Casper

1981

 United States

18½–9½

 Europe

England

Walton Heath Golf Club, Walton-on-the-Hill, Surrey

 John Jacobs

Dave Marr

1983

 United States

14½–13½

 Europe

United States

PGA National Golf Club, Palm Beach Gardens, Florida

 Tony Jacklin

Jack Nicklaus

1985

 Europe

16½–11½

 United States

England

The Belfry, Brabazon Course, Wishaw, Warwickshire

 Tony Jacklin

Lee Trevino

1987

 Europe

15–13

 United States

United States

Muirfield Village, Dublin, Ohio

 Tony Jacklin

Jack Nicklaus

1989

 Europe[A]

14–14

 United States

England

The Belfry, Brabazon Course, Wishaw, Warwickshire

 Tony Jacklin

Raymond Floyd

1991

 United States

14½–13½

 Europe

United States

Kiawah Island Golf Resort, Ocean Course, Kiawah Island, South Carolina

 Bernard Gallacher

Dave Stockton

1993

 United States

15–13

 Europe

England

The Belfry, Brabazon Course, Wishaw, Warwickshire

 Bernard Gallacher

Tom Watson

1995

 Europe

14½–13½

 United States

United States

Oak Hill Country Club, East Course, Rochester, New York

 Bernard Gallacher

Lanny Wadkins

1997

 Europe

14½–13½

 United States

Spain

Valderrama Golf Club, Sotogrande, Andalusia

 Seve Ballesteros

Tom Kite

1999

 United States

14½–13½

 Europe

United States

The Country Club, Composite Course, Brookline, Massachusetts

 Mark James

Ben Crenshaw

2002

 Europe

15½–12½

 United States

England

The Belfry, Brabazon Course, Wishaw, Warwickshire

 Sam Torrance

Curtis Strange

2004

 Europe

18½–9½

 United States

United States

Oakland Hills Country Club, South Course, Bloomfield Hills, Michigan

 Bernhard Langer

Hal Sutton

2006

 Europe

18½–9½

 United States

Republic of Ireland

K Club, Palmer Course, Straffan, County Kildare

 Ian Woosnam

Tom Lehman

2008

 United States

16½–11½

 Europe

United States

Valhalla Golf Club, Louisville, Kentucky

 Nick Faldo

Paul Azinger

2010

 Europe

14½–13½

 United States

Wales

Celtic Manor Resort, Twenty Ten Course, Newport

 Colin Montgomerie

Corey Pavin

2012

 Europe

14½–13½

 United States

United States

Medinah Country Club, Course 3, Medinah, Illinois

 José María Olazábal

Davis Love III

2014

 Europe

16½–11½

 United States

Scotland

Gleneagles, PGA Centenary Course, Perth & Kinross

 Paul McGinley

Tom Watson

2016

 United States

17–11

 Europe

United States

Hazeltine National Golf Club, Chaska, Minnesota

 Darren Clarke

Davis Love III

2018

 Europe

17½–10½

 United States

France

Le Golf National, Albatros Course, Saint-Quentin-en-Yvelines

 Thomas Bjørn

Jim Furyk

text: Results by team[edit]

text:
Team

From

To

Matches

Wins

Losses

Ties

 United States

1927

2018

42

26

14

2

 Great Britain/ Great Britain &  Ireland

1927

1977

22

3

18

1

 Europe

1979

2018

20

11

8

1

text: Venues[edit]

text: Maps of Ryder Cup venues.

text: Notes[edit]

text: A.   a b  In the event of a match ending in a tie, the team who last won the Ryder Cup retains the Cup.[51]


document_title: Extreme points of North America

question_text: what is the southern most point in north america

text: Extreme points of North America

text: North America and surrounding islands[edit]

text:
Northernmost point — Kaffeklubben Island, Greenland 83°40′N 29°50′W / 83.667°N 29.833°W / 83.667; -29.833 (Kaffeklubben Island). Although politically part of the Kingdom of Denmark, Greenland is geologically part of the North American plate. If Greenland is excluded from North America, the northernmost point is Cape Columbia, Ellesmere Island, Nunavut, Canada 83°8′N 74°13′W / 83.133°N 74.217°W / 83.133; -74.217 (Cape Columbia).
Southernmost point — Cocos Island, Costa Rica 5°31′8″N 87°4′18″W / 5.51889°N 87.07167°W / 5.51889; -87.07167 (Cocos Island)
Westernmost point — The westernmost point depends on the definition of "westernmost". If following the International Date Line, it would be Cape Wrangell on Attu Island, Alaska, United States 52°55′28″N 172°28′22″E / 52.92444°N 172.47278°E / 52.92444; 172.47278 (Cape Wrangell). However, if the border between east and west is defined by the 180th meridian, the westernmost point is the West Point of Amatignak Island 51°17′N 179°9′W / 51.283°N 179.150°W / 51.283; -179.150 (West Point of Amatignak Island), as Attu Island is in the Eastern Hemisphere.
Easternmost point — Nordostrundingen, Greenland 81°26′25″N 11°29′22″W / 81.44028°N 11.48944°W / 81.44028; -11.48944 (Nordostrundingen). If Greenland is excluded, then the easternmost point is Cape Spear, Newfoundland, Canada 47°31′25″N 52°37′10″W / 47.52361°N 52.61944°W / 47.52361; -52.61944 (Cape Spear). Again, if one uses the technical definition of longitude, it is Pochnoi Point on Semisopochnoi Island, Alaska, 51°57′N 179°52′E / 51.950°N 179.867°E / 51.950; 179.867 (Pochnoi Point) since the state stretches into the Eastern Hemisphere.

text: Continental North America[edit]

text:
Northernmost point — Zenith Point, Canada 72°0′0″N 94°38′59″W / 72.00000°N 94.64972°W / 72.00000; -94.64972 (Zenith Point)
Southernmost point — Punta Mariato, Panama 7°12′32″N 80°53′10″W / 7.20889°N 80.88611°W / 7.20889; -80.88611 (Punta Mariato)
Westernmost point — Cape Prince of Wales, Alaska 65°35′47″N 168°5′5″W / 65.59639°N 168.08472°W / 65.59639; -168.08472 (Cape Prince of Wales)
Easternmost point — Cape Saint Charles, Labrador 52°13′3″N 55°37′15″W / 52.21750°N 55.62083°W / 52.21750; -55.62083 (Cape Saint Charles)

text: Highest points[edit]

text:
Denali (Mount McKinley), Alaska, United States 63°4′10″N 151°0′26″W / 63.06944°N 151.00722°W / 63.06944; -151.00722 (Mount McKinley) — highest summit of North America at 6,190.5 m (20,310 feet).[1]
Pico de Orizaba (Volcán Citlaltépetl),[note 1][2] Puebla and Veracruz, Mexico 19°1′50″N 97°16′11″W / 19.03056°N 97.26972°W / 19.03056; -97.26972 (Pico de Orizaba) — highest volcano summit of North America at 5,636 m (18,491 feet).
Grays Peak,[note 2][3][4][note 3] Colorado, United States 39°38′2″N 105°49′3″W / 39.63389°N 105.81750°W / 39.63389; -105.81750 (Grays Peak) — highest point on the Continental Divide of North America at 4,352 m (14,278 feet).
Volcán Tajumulco,[note 4][5] San Marcos, Guatemala 15°2′37″N 91°54′12″W / 15.04361°N 91.90333°W / 15.04361; -91.90333 (Volcán Tajumulco) — highest summit of Central America at 4,220 m (13,850 feet).
Gunnbjørn Fjeld,[note 5][6] Sermersooq, Island of Greenland, Greenland 68°55′10″N 29°53′55″W / 68.91944°N 29.89861°W / 68.91944; -29.89861 (Gunnbjørn Fjeld) — highest island summit of the Americas and the Western Hemisphere and highest summit of the entire Arctic at 3,694 m (12,119 feet).
Pico Duarte,[note 6][7] Dominican Republic, Hispaniola 19°1′23″N 70°59′53″W / 19.02306°N 70.99806°W / 19.02306; -70.99806 (Pico Duarte) — highest summit of the Caribbean at 3,175 m (10,417 feet).
Ixchiguán, San Marcos Department, Guatemala — highest town of North America at 3200m  m (10,500 feet)
Leadville, Colorado, United States 39°14′50″N 106°17′30″W / 39.24722°N 106.29167°W / 39.24722; -106.29167 (Leadville, Colorado) — highest city of North America at 3094 m (10,152 feet)
Lake County Airport, Colorado, United States 39°13′13″N 106°19′00″W / 39.22028°N 106.31667°W / 39.22028; -106.31667 (Lake County Airport) — highest airfield of North America at 3026 m (9,927 feet)

text: Lowest points[edit]

text:
Badwater Basin, Death Valley, California, United States 36°14′23″N 116°50′5″W / 36.23972°N 116.83472°W / 36.23972; -116.83472 (Badwater Basin) — lowest land surface of North America at −85.0 m (−279 feet)[8]
Salton Sea, California, United States 33°19′59″N 115°50′3″W / 33.33306°N 115.83417°W / 33.33306; -115.83417 (Salton Sea) — lowest lake of North America at −69 m (−226 feet)
Furnace Creek Airport, California, United States 36°27′50″N 116°52′53″W / 36.46389°N 116.88139°W / 36.46389; -116.88139 (Furnace Creek Airport) — lowest airfield of the Americas at −64 m (−210 feet)
Furnace Creek,[9] California, United States 36°27′29″N 116°52′15″W / 36.45806°N 116.87083°W / 36.45806; -116.87083 (Furnace Creek, California) — lowest settlement of the Americas at −58 m (−190 ft)
Calipatria, California, United States 33°07′32″N 115°30′51″W / 33.12556°N 115.51417°W / 33.12556; -115.51417 (Calipatria, California) — lowest city of the Americas at −56 m (−184 feet)
Lago Enriquillo, Dominican Republic, Hispaniola 18°30′N 71°35′W / 18.500°N 71.583°W / 18.500; -71.583 (Lago Enriquillo) — lowest lake on an island and lowest surface point on any ocean island on Earth at −27 m (−89 feet)
New Orleans, Louisiana, United States 29°58′N 90°03′W / 29.967°N 90.050°W / 29.967; -90.050 (New Orleans, Louisiana) — lowest city of the Americas with an average elevation of −0.5 m (−1.5 feet)
Isthmus of Rivas, Rivas, Nicaragua 12°1′N 86°27′W / 12.017°N 86.450°W / 12.017; -86.450 (Isthmus of Rivas) — lowest pass between Caribbean Sea and Pacific Ocean (on the Continental Divide of the Americas) at 56 m (184 feet)
Great Slave Lake bottom, Northwest Territories, Canada 61°40′N 114°00′W / 61.667°N 114.000°W / 61.667; -114.000 (Great Slave Lake) — lowest fresh water point of the Americas at −458 m (−1,503 feet)

text: Other points[edit]

text:
The geographic center of the North American continent is located at 48°10′N 100°10′W / 48.167°N 100.167°W / 48.167; -100.167 (Geographic center of the North American continent), about 6 miles west of Balta in Pierce County, North Dakota, United States.
The North American pole of inaccessibility is located at 43°22′N 101°58′W / 43.367°N 101.967°W / 43.367; -101.967 (North American pole of inaccessibility), about eleven miles southeast of the town of Kyle on the Pine Ridge Indian Reservation in Bennett County, South Dakota, United States, 1650 km (1025 miles) from the nearest coastlines.

text: Islands[edit]

text:
Island of Greenland 68°55′10″N 29°53′55″W / 68.91944°N 29.89861°W / 68.91944; -29.89861 (Island of Greenland) — most extensive island on Earth at 2,130,800 km2 (822,700 square miles) and tallest island of Western Hemisphere. Highest point is Gunnbjørn Fjeld at 12,118 feet (3,694 m).
Island of Cuba 21°30′N 80°0′W / 21.500°N 80.000°W / 21.500; -80.000 (Island of Cuba) — most extensive island of the Caribbean at 104,556 km2 (40,369 square miles). Highest point is Pico Turquino at convert 6,480 feet (1,980 m).
Hispaniola 19°1′23″N 70°59′53″W / 19.02306°N 70.99806°W / 19.02306; -70.99806 (Hispaniola) — tallest island of the Caribbean and second most extensive island of the Caribbean at 76,480 km2 (29,529 square miles). Highest peak is Pico Duarte at 10,417 ft (3,175 m).
Manitoulin Island in Lake Huron, Ontario, Canada 45°46′N 82°12′W / 45.767°N 82.200°W / 45.767; -82.200 (Manitoulin Island) — most extensive lake island on Earth at 2,766 km2 (1,068 square miles)
Unimak Island - highest point is Shishaldin Volcano at 9,373 ft (2,857 m).
Ellesmere Island - highest point is Barbeau Peak at 8,583 ft (2,616 m).
Jamaica - highest point is Blue Mountain Peak at 7,402 ft (2,256 m).
Axel Heiberg Island - highest point is Outlook Peak at 7,251 ft (2,210 m).
Vancouver Island - highest point is Golden Hinde at 7,211 ft (2,198 m).
Baffin Island - highest point is Mount Odin at 7,044 ft (2,147 m).
Umnak Island - highest point is Mount Vsevidof at 6,920 ft (2,110 m).
Unalaska Island - highest point is Makushin Volcano at 6,680 ft (2,040 m).

text: Lakes[edit]

text:
Lake Superior, Canada and the United States 47°45′N 87°30′W / 47.750°N 87.500°W / 47.750; -87.500 (Lake Superior) — most voluminous lake in Western Hemisphere at 11,600 km3 (2,800 cubic miles)
Great Slave Lake, Northwest Territories, Canada 61°40′N 114°00′W / 61.667°N 114.000°W / 61.667; -114.000 (Great Slave Lake) — deepest lake in Western Hemisphere at 614 m (2,014 feet)
Lake Michigan–Huron, Canada and the United States 45°49′N 84°45′W / 45.817°N 84.750°W / 45.817; -84.750 (Lake Michigan–Huron) — most extensive lake in Western Hemisphere and the most extensive fresh water lake on Earth at 117,702 km2 (45,445 square miles)
Nettilling Lake on Baffin Island, Nunavut, Canada 66°30′N 70°50′W / 66.500°N 70.833°W / 66.500; -70.833 (Nettilling Lake) — most extensive lake on an island on Earth at 5,066 km2 (1,956 square miles)
Great Salt Lake, Utah, United States 31°10′N 112°35′W / 31.167°N 112.583°W / 31.167; -112.583 (Great Salt Lake) — most extensive endorheic lake at 4,400 km2 (1,700 square miles)
Lake Manitou on Manitoulin Island in Lake Huron, Ontario, Canada 45°46′42″N 81°59′30″W / 45.77833°N 81.99167°W / 45.77833; -81.99167 (Lake Manitou) — most extensive lake on an island in a lake on Earth at 104 km2 (40 square miles)

text: Rivers[edit]

text:
Mississippi Basin, Canada and the United States 29°9′4″N 89°15′12″W / 29.15111°N 89.25333°W / 29.15111; -89.25333 (Mississippi River) — most extensive river basin at 2,981,076 km2 (1,151,000 square miles)
Mississippi-Missouri-Jefferson Rivers, United States 29°9′4″N 89°15′12″W / 29.15111°N 89.25333°W / 29.15111; -89.25333 (Mississippi-Missouri-Jefferson Rivers) — longest river system at 6,275 km (3,902 miles)
Missouri River, United States 38°48′49″N 90°7′11″W / 38.81361°N 90.11972°W / 38.81361; -90.11972 (Missouri River) — longest main stem river at 3,768 km (2,341 miles)
Mississippi River, United States 29°9′4″N 89°15′12″W / 29.15111°N 89.25333°W / 29.15111; -89.25333 (Mississippi River) — longest Gulf of Mexico main stem river at 3,544 km (2,202 miles)
Yukon River, Canada and the United States 62°35′55″N 164°47′40″W / 62.59861°N 164.79444°W / 62.59861; -164.79444 (Yukon River) — longest Bering Sea main stem river at 3,185 km (1,979 miles)
Nelson River, Manitoba, Canada 57°5′5″N 92°30′8″W / 57.08472°N 92.50222°W / 57.08472; -92.50222 (Nelson River) — longest Hudson Bay main stem river at 2,575 km (1,600 miles)
Colorado River, United States and Mexico 31°48′57″N 114°48′22″W / 31.81583°N 114.80611°W / 31.81583; -114.80611 (Colorado River) — longest Gulf of California main stem river at 2,330 km (1,450 miles)
Columbia River, Canada and the United States 46°14′39″N 124°3′29″W / 46.24417°N 124.05806°W / 46.24417; -124.05806 (Columbia River) — longest Pacific Ocean main stem river at 2,000 km (1,243 miles)
Mackenzie River, Northwest Territories, Canada 68°56′23″N 136°10′22″W / 68.93972°N 136.17278°W / 68.93972; -136.17278 (Mackenzie River) — longest Arctic Ocean main stem river at 1,738 km (1,080 miles)
Saint Lawrence River, United States and Canada 49°40′N 64°30′W / 49.667°N 64.500°W / 49.667; -64.500 (Saint Lawrence River) — longest Atlantic Ocean main stem river at 965 km (600 miles)

text: Extreme points of North American countries[edit]

text:
Extreme points of Canada
Extreme points of Cuba
Extreme points of Greenland
Extreme points of Mexico
Extreme points of the United States